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diff --git a/impl/src/test/java/io/opencensus/internal/DisruptorEventQueueTest.java b/impl/src/test/java/io/opencensus/internal/DisruptorEventQueueTest.java
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+/*
+ * Copyright 2016, Google Inc.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.opencensus.internal;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+/** Unit tests for {@link DisruptorEventQueue}. */
+@RunWith(JUnit4.class)
+public class DisruptorEventQueueTest {
+  // Simple class to use that keeps an incrementing counter. Will fail with an assertion if
+  // increment is used from multiple threads, or if the stored value is different from that expected
+  // by the caller.
+  private static class Counter {
+    private int count;
+    private volatile long id; // stores thread ID used in first increment operation.
+
+    public Counter() {
+      count = 0;
+      id = -1;
+    }
+
+    // Increments counter by 1. Will fail in assertion if multiple different threads are used
+    // (the EventQueue backend should be single-threaded).
+    public void increment() {
+      long tid = Thread.currentThread().getId();
+      if (id == -1) {
+        assertThat(count).isEqualTo(0);
+        id = tid;
+      } else {
+        assertThat(id).isEqualTo(tid);
+      }
+      count++;
+    }
+
+    // Check the current value of the counter. Assert if it is not the expected value.
+    public void check(int value) {
+      assertThat(count).isEqualTo(value);
+    }
+  }
+
+  // EventQueueEntry for incrementing a Counter.
+  private static class IncrementEvent implements EventQueue.Entry {
+    private final Counter counter;
+
+    IncrementEvent(Counter counter) {
+      this.counter = counter;
+    }
+
+    @Override
+    public void process() {
+      counter.increment();
+    }
+  }
+
+  @Test
+  public void incrementOnce() {
+    Counter counter = new Counter();
+    IncrementEvent ie = new IncrementEvent(counter);
+    DisruptorEventQueue.getInstance().enqueue(ie);
+    // Sleep briefly, to allow background operations to complete.
+    try {
+      Thread.sleep(500);
+    } catch (InterruptedException ex) {
+      Thread.currentThread().interrupt();
+    }
+    counter.check(1);
+  }
+
+  @Test
+  public void incrementTenK() {
+    final int tenK = 10000;
+    Counter counter = new Counter();
+    for (int i = 0; i < tenK; i++) {
+      IncrementEvent ie = new IncrementEvent(counter);
+      DisruptorEventQueue.getInstance().enqueue(ie);
+    }
+    // Sleep briefly, to allow background operations to complete.
+    try {
+      Thread.sleep(500);
+    } catch (InterruptedException ex) {
+      Thread.currentThread().interrupt();
+    }
+    counter.check(tenK);
+  }
+}